Twenty-five Algerian and foreign hostages were announced dead Sunday after Algerian special forces staged a final assault against Islamist hostage-takers Saturday at the Saharan gas plant of In Amenas, Algeria.

Mokhtar Belmokhtar, dubbed Mr. Marlboro, head of the self-initiated Islamist al-Multahemeen (the masked) Brigade, claimed responsibility for the January 17 gas plant invasion, as a reprisal for the continuing french intervention in Mali since January 11th.

Islamist militants had allegedly taken hostages as a bargaining chip to coerce France into negotiations.

Algerian Minister of Communications Mohammed Said reported that the Islamist militants, of at least six different nationalities, included explosive specialists who planted mines during the operation.

Belmokhtar had released a video last Tuesday requesting negotiations and praising his men for “breaking the pride of the arrogant forces.”

“Our nation should know that unless we resist, we are finished,” he said in the video.

“So how can the West address us in the language of guns and cannons while we beg for negotiations and normalization?” he continued.

Belmokhtar, nicknamed "Mr. Marlboro" for allegedly trafficking cigarettes, had previously been sentenced to life imprisonment in absentia by Algerian courts for the killing of 10 border guards in 2008.

The Algerian special forces, reportedly forced to intervene after a fire had been declared in the plant, battled with the Islamists over a four-day period that ended on Saturday and left at least 66 dead.

685 Algerian employees and 107 foreigners were freed, but at least 25 hostages were killed since Wednesday along with 32 militants.

Among the 25 killed, so far confirmed, were American, Romanian, British and Algerian nationals.

Nine Japanese expatriates working on the plant were also executed on Wednesday, after three had attempted to escape a bus that was headed to the In Amenas airport on direction of the Islamists.

The fate of other hostages, including five Norwegians, two Malaysians, and three British citizens, is still unknown but the actual death toll is expected to be higher than so far reported.

The Algerian army also said it had captured five kidnappers that were still alive on Sunday inside the plant with at least three others still at large, Algerian TV reported.

Some Western governments had expressed frustration at not being informed of the Algerian authorities' plans to storm the complex. But France, which is fighting Islamist rebels across the desert in Mali, joined Britain in playing down any suggestion that the response from Algeria - the main military power in the Sahara region - had been over-hasty or heavy-handed.

"What everyone needs to know is that these terrorists who attacked this gas plant are killers who pillage, rape, plunder and kill. The situation was unbearable," French Foreign Minister Laurent Fabius said.

"It's easy to say that this or that should have been done. The Algerian authorities took a decision and the toll is very high but I am a bit bothered ... when the impression is given that the Algerians are open to question. They had to deal with terrorists," he told Europe 1 radio in an interview.